Energized Obama tries to rebound after Wednesday's debate

President Barack Obama waves as he arrives at a campaign rally in Denver, Thursday, Oct. 4, 2012.

By NBC's Kristen Welker

DENVER -- A fired-up President Barack Obama spoke to a crowd of more than 12,000 at a Denver campaign event Thursday and seemed to exude the energy and aggressiveness that many of his supporters felt was missing at last night's presidential debate.

Trying to rebound from what many called a listless performance last night, Obama argued today that the Mitt Romney who appeared at the debate was not the “real Mitt Romney.”

“When I got on stage, I met this very spirited fellow who claimed to be Mitt Romney,” he said. “But it couldn’t have been Mitt Romney, because the real Mitt Romney has been running around the country for the year, promising $5 trillion dollars in tax cuts that favor the wealthy. The fellow on stage last night didn’t seem to know anything about that.”

The president dedicated the first part of his speech to retroactively rebutting Romney’s debate talking points.

President Obama speaks to supporters in Denver, Colo., following the first debate of the 2012 presidential race.

Last night, Romney said his plans to trim the deficit wouldn’t mean teacher cuts: “I reject the idea that I don’t believe in great teachers or more teachers. Every school district, every state should make that decision on their own.”

Romney had the final word on the matter last night, but today Obama told his supporters: “The real Mitt Romney said we don’t need anymore teachers in our classrooms ... But the fellow on stage last night, he loves teachers, can’t get enough of them.”

Last night, Obama also missed an opportunity to highlight his opponent’s personal tax records after Gov. Romney said, “I’ve been in business for 25 years. I have no idea what you’re talking about. I maybe need to get a new accountant ... but the idea that you get a break for shipping jobs overseas is simply not the case."

Today, Mr. Obama fired off this retort: “We know for sure it was not the real Mitt Romney because he seems to be doing just fine with his current accountant.”

Kevin Lamarque / Reuters

President Barack Obama greets supporters during a campaign rally in Denver on Oct. 4, 2012.

And while Romney drew a lot of public criticism for suggesting his deficit reductions would include stripping federal funding for PBS -- and by extension “Big Bird” -- Obama did not challenge him on the point until today: “He said he’d eliminate funding for public television... I mean thank goodness someone is finally getting tough on ‘Big Bird.’ ”

The crowd responded to the president’s jabs with loud cheers, but for many the disappointment from the president’s debate performance had already set in.